Substance abuse has had devastating consequences in the U.S. and the world. There is growing evidence of specific genetic disposition to substance dependence. Recent developments in the production of "DNA-chip" or "gene-chip" systems suggest the use of hybridization-array approaches in identifying genetic factors in addiction, the evaluation of genetic variability among populations at risk and the possible design of genetic treatment for substance abuse. Although efforst are currently underways to miniaturize exist gene probe instrumentation, there is a need to develop low cost, customizable sensors capable of rapid evaluation of genes implicated substance abuse. To meet this need, American Research Corporation of Virginia has suggested the development of miniaturized array hybridization dectector. The proposal is innovative that is based on the combination of fluorescent intercalation technology, a patented waveguide-based array detector and micromachined methods of automated chip production to enable rapid, sensitive detection of hybridization of oligonucleotide sequences. The goal of the Phase I program is to demonstrate a low-cost customizable approach to gene-chip fabrication.